code: def test_load_stream(self):
      dat0 = np.random.rand(10, 1, 4, 4)
      dat1 = np.random.rand(10, 1, 4, 4)
  
      npzfile = BytesIO()
      np.savez_compressed(npzfile, dat0=dat0, dat1=dat1)
      npzfile.seek(0)
  
      npzds = NPZDictItemDataset(
          npzfile, {"dat0": "images", "dat1": "seg"}
      )
  
      item = npzds[0]
  
      np.testing.assert_allclose(item["images"].shape, (1, 4, 4))
      np.testing.assert_allclose(item["seg"].shape, (1, 4, 4))
  
file_path: MONAI/tests/test_npzdictitemdataset.py
imports: from __future__ import annotations
  import tempfile
  import unittest
  from io import BytesIO
  import numpy
  from monai.data import NPZDictItemDataset
label_desc: Use image node_id 1 for calling the TestNPZDictItemDataset obj's underlying member method code with example usage: obj.test_load_stream() without return types